| abstract |
A drill bit is provided that is constructed and arranged to form a bore in a bone by cutting and moving bone fragments to a wall of the bore. The drill bit includes an elongated shaft having a distal portion and a proximal portion. The proximal portion has a constant diameter. A cutting tip is defined at the free end of the distal portion. A segment of the distal portion has transverse cross-sectional area less than that of the proximal portion. The distal portion segment also includes a surface to facilitate movement of the bone fragments towards the proximal portion of the shaft. When the drill bit enters the bone so as to form the bore and is moved an amount such that the distal portion is disclosed completely within the bore, a space is defined between the wall of the bore and a periphery of the segment of the distal portion which receives the bone fragments. Further insertion of the drill bit into the bone causes the bone fragments to move along the surface of the distal portion segment to the outer cylindrical surface of the proximal portion which compacts the bone fragments against the wall of the bore. |